Laterally proximized aluminum tunnel junctions

J. V. Koski, J. T. Peltonen, M. Meschke, J. P. Pekola

This letter presents experiments on junctions fabricated by a technique that enables the use of high-quality aluminum oxide tunnel barriers with normal metal electrodes at low temperatures. Inverse proximity effect is applied to diminish the superconductivity of an aluminum dot through a clean lateral connection to a normal metal electrode. To demonstrate the effectiveness of this method, fully normal-state single electron transistors (SETs) and normal metal-insulator-superconductor (NIS) junctions applying proximized Aljunctions were fabricated. The transport characteristics of the junctions were similar to those obtained from standard theoreticalmodels of regular SETs and NIS junctions